package org.mca.mcaweb.util;

import java.security.MessageDigest;


public final class PasswordHelper {
	
	private static PasswordHelper instance;
	
	private PasswordHelper() {
	}

	private static String convertToHex(byte[] data) {
		StringBuffer buf = new StringBuffer();
		for (int i = 0; i < data.length; i++) {
			int halfbyte = (data[i] >>> 4) & 0x0F;
			int two_halfs = 0;
			do {
				if ((0 <= halfbyte) && (halfbyte <= 9)){
					buf.append((char) ('0' + halfbyte));
				}else{
					buf.append((char) ('a' + (halfbyte - 10)));
				}
				halfbyte = data[i] & 0x0F;
			}
			while(two_halfs++ < 1);
		}
		return buf.toString();
	} 
	 
	public synchronized String encryptMD5(String password) {
		MessageDigest md = null;
		try{
			md = MessageDigest.getInstance("MD5");
			md.update(password.getBytes("iso-8859-1"), 0, password.length());
		} catch (Exception e) {
			e.printStackTrace();
		}
		byte[] md5hash = new byte[64];
		md5hash = md.digest();
		return convertToHex(md5hash);
	} 

	
	public synchronized String encryptSHA(String password) {
		MessageDigest md = null;
		try {
			md = MessageDigest.getInstance("SHA");
			md.update(password.getBytes("iso-8859-1"), 0, password.length());
		} catch (Exception e) {
			e.printStackTrace();
		}
		byte[] md5hash = new byte[64];
		md5hash = md.digest();
		return convertToHex(md5hash);
	}


	public static synchronized PasswordHelper getInstance()	{
		if (instance == null) {
			return new PasswordHelper();
		} else {
			return instance;
		}
	}
}
